This invention relates to a class of cation-reordered, bismuth-containing compounds having a perovskite-type structure useful in oxidative dehydrogenation reactions and a process for their preparation. In addition, the invention relates to a process for selectively producing aromatic compounds from acyclic olefins, preferably propylene and isobutylene.
During a typical petroleum refining operation large quantities of low molecular weight paraffins and olefins are produced. Unlike paraffins which may be sold for fuels, olefins have undesirable combustion properties which hamper their potential use as fuels. Thus, much research effort has been directed to upgrading the olefins, either for use as fuel or as chemical intermediates in the chemical industry. For those olefins containing three and four carbon atoms much research has been directed toward obtaining reaction products such as dimer and aromatic products having greater potential commercial value, with bismuth oxide representing a conventional oxidation catalyst, particularly for producing dimers.
Oxidative conversions of unsaturated hydrocarbons have recently been conducted using various catalyst combinations. A recently published comprehensive review article on oxidative dehydrogenation of olefins is E. A. Mamedov, Russ. Chem. Reviews, 50, 291 (1981), which lists numerous references disclosing use of catalysts containing bismuth oxide in combination with other elements to convert olefins to dienes and aromatic products in the presence or absence of molecular oxygen.